PRIME Minister Gordon Brown last night chaired a meeting of the Government's Cobra emergency contingencies committee to discuss the response to the flooding.

Present for the meeting were Environment Secretary Hilary Benn, Community Secretary Hazel Blears, Transport Secretary Ruth Kelly and Floods Recovery Minister John Healey.

The ministers also heard - by conference call link - from Tim Brain, the head of the Gold Command emergency response team in Gloucestershire, one of the areas worst hit by the torrential downpours.

A Downing Street spokes-man said the meeting was devoted to updating ministers on the situation, and Mr Benn, Ms Blears and Mr Healey reported back from their visits to flood-hit areas.

The Prime Minister is expected to visit flood affected areas today, though Downing Street declined to reveal exactly where he would go.

Last night, the River Severn was expected to flood in the Gloucester area as it rose to record levels.

Meanwhile, Severn Trent Water said that a water treatment works in Tewkesbury had become inoperable after it was deluged by flood water.

Areas of Oxford and parts of nearby Abingdon, Bladon and Kidlington were flooded yesterday and people in Witney were evacuated on Saturday night.

Water shortages in Gloucester, Cheltenham and Tewkesbury will last for the next few days.

About 600 water tanks were being drafted in with help from the military.

And Sutton and East Surrey Water warned 80,000 households and businesses in its Sutton supply area to boil tap water before drinking it after the firm discovered rain had leaked into a tank of water that had gone to customers.

Mr Benn warned that the emergency was not over.

Speaking as he visited Worcester city centre, he said residents should brace themselves for more flooding because more rain was predicted to hit the region last night.

The Government said that emergency workers had the resources they needed.

Evacuation measures were being put in place as the River Severn was expected to reach its highest level since floods in 1947.

At Gloucester Docks, more than 500 people gathered as roads were shut by police in the flood zone.

Ian Hancock and his partner, Carrie Douch, were concerned about further flooding.

Mr Hancock, 27, said: "We got flooded out two weeks ago, but it looks like it's someone else's turn this time. It's a surreal atmosphere. There's a lot of people here to watch what's going to happen."

The swollen river was rising at one centimetre an hour.

Mother-of-two Ms Douch, 26, said the couple had driven more than 15 miles to buy water following the closure of the water treatment plant.

She said: "The queues outside the supermarkets are horrendous. Everyone is desperate to get their hands on some water. We've heard stories of grown men pushing kids out of the way to get to bottles of the stuff - it's disgusting."

Tewkesbury has been cut off since the flooding began on Friday afternoon.

Gloucestershire Fire and Rescue service had ten boats in the area ferrying people around.

Several RAF helicopters helped to rescue people trapped in surrounding areas.

Despite water shortages and the imminent flooding in parts of Gloucester, police said the situation across the rest of the county was improving.

Opposition MPs have accused ministers of failing to prepare for the floods.

Tory leader David Cameron, who surveyed some of the damage kitted out in a suit and wellingtons yesterday, said: "People want answers."

Liberal Democrat leader Sir Menzies Campbell said the Government's performance over the flooding was "pretty mixed".

Baroness Young, chief executive of the Environment Agency, said that flooding on this scale may become more commonplace.

* The cost of the summer floods could exceed £2bn, making 2007 one of the worst years for insurers, it was predicted last night.

A spokeswoman for the the Association of British Insurers said: "With June and July combined, we could see losses in excess of £2bn.